Non Gmail IMAP accounts never populateSupport

I am signed into my primary Google account for Gmail/Calendar/Contacts/Google Voice/Google Talk, etc. I then tried setting up a couple of IMAP accounts for work-related stuff via the native mail app. All of my credentials were accepted and the accounts were successfully created. I can even pull up my folder structure using Menu > Show Folders. The folders, including the Inbox never populate though.

After this experience I then tried setting up a secondary Gmail account using IMAP settings and it populated beautifully and immediately.

So I tried K-9 mail and the accounts populated as expected. K-9 is actually quite nice and a great alternative, and so at least I've got my mail, but I find it strange that the native mail app wouldn't work.

What's up with that!? Is there some issue with non Gmail IMAP accounts?